Continued Physical Activity Benefits Older Adults at Risk of Alzheimer’s, Study Suggests

Marta Figueiredo, PhD avatar

by Marta Figueiredo, PhD |

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Physical activity and Alzheimer's

Continued activity improves physical health in older adults at risk of Alzheimer’s, which in turn can potentially reduce their risk of developing the disease, according to results of an Australian clinical trial.

The study, “A Randomized Controlled Trial of Adherence to a 24-Month Home-Based Physical Activity Program and the Health Benefits for Older Adults at Risk of Alzheimer’s Disease: The AIBL Active-Study,” was published in the Journal of Alzheimer’s Disease.

Currently, there is no effective pharmacological therapy to prevent cognitive decline and Alzheimer’s disease, but a third of Alzheimer’s cases worldwide are estimated to be associated with modifiable risk factors, such as physical inactivity and mid-life obesity. Introducing lifestyle modifications to reduce these risk factors can potentially work as a strong preventative against Alzheimer’s disease.

Increasing physical activity has the potential not only to reduce the risk from inactivity but also from obesity, as it reduces fat mass and increases muscle mass.

Previous studies have shown that physical activity interventions can improve physical and cognitive function in older adults with mild cognitive impairment or subjective memory complaints who are at increased risk of Alzheimer’s disease. But the success of these programs is dependent on the participant’s adherence to them.

Whether a long-term, home-based physical activity program would achieve high rates of adherence and the same physical benefits as previously reported in older adults at risk of developing Alzheimer’s remains unclear.

Researchers in Australia evaluated the adherence of older adults at risk of Alzheimer’s to a two-year, home-based physical activity program and its physical health benefits.

The program gradually increased minutes of moderate walking to at least 150 minutes a week, preferably through three sessions of 50 minutes per week. Participants wore a pedometer to measure their number of steps.

The randomized, controlled clinical trial, called the AIBL Active trial, evaluated whether this type of program could delay the progression of cerebrovascular disease in older adults with mild memory problems.

Participants were recruited from the Melbourne-based Australian Imaging, Biomarkers and Lifestyle (AIBL) study, an observational study to discover biomarkers, cognitive features, and lifestyle and health factors associated with the development of Alzheimer’s disease.

Researchers focused only on the trial’s secondary goals, including the determination of participants’ retention, adherence to the program, physical activity, fitness, body mass, and body composition, at the beginning of the study and at several points until its end.

Retention was defined as the number of participants remaining in the study at each point; adherence as the rate of completion of the prescribed number of minutes of activity. Physical performance was assessed with a battery of tests.

The study enrolled 106 people 60 or older (57 women and 49 men) at risk of Alzheimer’s disease. Individuals had mild cognitive impairment or subjective memory complaints, and at least one cerebrovascular risk factor, such as physical inactivity, obesity, hypertension, heart disease, type II diabetes, smoking, or high cholesterol.

Seventy-one (67%) of participants were overweight or obese and 34 (31.5%) were classified as low active or sedentary.

Individuals were randomized to follow the physical program (55 participants) or continue with their usual physical activity (51 participants).

Higher retention and adherence rates were observed throughout the physical program, with a two-year retention rate of 97.2% and a median adherence of 91.67%.

The results also showed that participants following the physical activity program had significantly greater improvement in physical activity levels, leg strength, fat distribution and reduction of fat mass, compared with those who continued their normal physical activity.

Data showed that long-term adherence in this population is achievable and was associated with physical health benefits that can reduce the risk of Alzheimer’s disease.

These results, if confirmed in future trials, highlight “the potential of this modest, easily accessible, and acceptable walking program to be used in programs targeting older adults, in particular those with [mild cognitive impairment] or [subjective memory complaints] to achieve improved health status and the prevention of disability,” researchers said.

The team also noted that it is important to work on the development of effective strategies to promote sustained physical activity in this population.